[olddog]

Tom Kirkham started a thread in the EFI and tuning section. He left several links a few posts later. There is a lot of reading, but the best info I have read to date. I still have a few questions though.

Bottom line is that your engine needs a bunch of advance at low load. That is partly to do with the lean fuel mixture. So no **** your engine runs better with a lot of advance. It may like as much as 52 deg at 2500 rpm and low load conditions. The problem is that at WOT the rich dense fuel charge burns much faster and the engine can only tollerate 35ish deg. Too much timing breaks engines, as you have already learned the hard way. Too little timing will make it run hot and slugish.

For mechanical only advance you must tune it only for WOT operation and let it run poorly at light load conditions. Big cams due to exhaust dilution from the overlap may need 16 to 18 initial, but do not go higher.

If you want it to run good at light load, get a vacuum advance on it.

I think the articals will answer all your questions and support what I have said. Good luck!